場景:在springboot多模塊中使用getBean獲取bean導(dǎo)致空指針異常。
@Test
public void test1(){
IUserService userService = SpringContextHolder.getBean(UserServiceImpl.class);
User user = userService.getUserByMobile("18782080356");
System.out.println(user);
}
假如有個(gè)工程有common模塊和admin(啟動(dòng)類模塊)模塊,獲取getBean的類在admin中,則不會(huì)報(bào)空指針,如果在common模塊中,在admin模塊中調(diào)用,則會(huì)報(bào)空指針異常,解決方法,使用@Import導(dǎo)入getBean方法所在的類
@SpringBootApplication
@Import(SpringContextHolder.class)
public class AdminApplication {
public static void main(String[] args) {
SpringApplication.run(OathServiceApplication.class, args);
}
}
import org.springframework.aop.framework.AopContext;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.NoSuchBeanDefinitionException;
import org.springframework.beans.factory.config.BeanFactoryPostProcessor;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.stereotype.Component;
import java.lang.annotation.Annotation;
import java.util.Map;
/**
* spring工具類 方便在非spring管理環(huán)境中獲取bean
*
* @author ruoyi
*/
@Component
public final class SpringContextHolder implements BeanFactoryPostProcessor
{
/** Spring應(yīng)用上下文環(huán)境 */
private static ConfigurableListableBeanFactory beanFactory;
@Override
public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException
{
SpringContextHolder.beanFactory = beanFactory;
}
/**
* 獲取對象
*
* @param name
* @return Object 一個(gè)以所給名字注冊的bean的實(shí)例
* @throws org.springframework.beans.BeansException
*
*/
@SuppressWarnings("unchecked")
public static <T> T getBean(String name) throws BeansException
{
return (T) beanFactory.getBean(name);
}
/**
* 獲取類型為requiredType的對象
*
* @param clz
* @return
* @throws org.springframework.beans.BeansException
*
*/
public static <T> T getBean(Class<T> clz) throws BeansException
{
T result = (T) beanFactory.getBean(clz);
return result;
}
/**
* 如果BeanFactory包含一個(gè)與所給名稱匹配的bean定義,則返回true
*
* @param name
* @return boolean
*/
public static boolean containsBean(String name)
{
return beanFactory.containsBean(name);
}
/**
* 判斷以給定名字注冊的bean定義是一個(gè)singleton還是一個(gè)prototype。 如果與給定名字相應(yīng)的bean定義沒有被找到,將會(huì)拋出一個(gè)異常(NoSuchBeanDefinitionException)
*
* @param name
* @return boolean
* @throws org.springframework.beans.factory.NoSuchBeanDefinitionException
*
*/
public static boolean isSingleton(String name) throws NoSuchBeanDefinitionException
{
return beanFactory.isSingleton(name);
}
/**
* @param name
* @return Class 注冊對象的類型
* @throws org.springframework.beans.factory.NoSuchBeanDefinitionException
*
*/
public static Class<?> getType(String name) throws NoSuchBeanDefinitionException
{
return beanFactory.getType(name);
}
/**
* 如果給定的bean名字在bean定義中有別名,則返回這些別名
*
* @param name
* @return
* @throws org.springframework.beans.factory.NoSuchBeanDefinitionException
*
*/
public static String[] getAliases(String name) throws NoSuchBeanDefinitionException
{
return beanFactory.getAliases(name);
}
public static Map<String, Object> getBeansWithAnnotation(Class<? extends Annotation> annotationType){
return beanFactory.getBeansWithAnnotation(annotationType);
}
/**
* 獲取aop代理對象
*
* @param invoker
* @return
*/
@SuppressWarnings("unchecked")
public static <T> T getAopProxy(T invoker)
{
return (T) AopContext.currentProxy();
}
}
``